Wafer Edge Coating Film Shaping to Prevent Inner Hump Formation
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Solution Overview
Problem
Existing methods for forming a coating film on the peripheral edge of a semiconductor wafer result in the inner peripheral end of the film rising, creating a protrusion (hump) that can lead to issues in subsequent processing and reduce yield.
Innovation Solution
A coating film forming apparatus that uses a gas nozzle to discharge gas from a position downstream of the coating liquid nozzle, shaping the film with an air flow to prevent the formation of a hump by collapsing it before solidification, ensuring uniform film thickness and preventing residue formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If coating liquid is supplied to the peripheral edge portion of a rotating wafer to form an annular coating film, then the coating film is formed along the circumference of the substrate, but the inner peripheral end of the coating film rises to form a hump
Solution Approach 1:
The gas nozzle supplies gas to the wafer surface at a position upstream in the rotational direction before the coating liquid is supplied. This preliminary gas flow prevents the coating liquid from accumulating and forming a hump at the inner peripheral end, counteracting the harmful effect before it occurs
Solution Approach 2:
Gas is introduced as an intermediary substance between the coating liquid supply and the wafer surface. The gas flow mediates the interaction by controlling the liquid flow and preventing hump formation while allowing the coating film to be formed uniformly
2Manufacturing precision
If a gas nozzle is added to supply gas to the wafer surface, then hump formation is suppressed, but the device complexity increases
Solution Approach 1:
The gas nozzle and coating liquid nozzle are integrated into a single processing system, with both nozzles working in coordination to achieve the coating film formation. The gas supply system is merged with the existing coating system rather than being completely separate
Solution Approach 2:
The gas flow serves multiple functions: it prevents hump formation, controls liquid flow distribution, and aids in uniform coating film formation. A single gas supply system performs multiple tasks that would otherwise require separate mechanisms
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The apparatus effectively suppresses the formation of humps, enhancing film uniformity and preventing yield loss by ensuring uniform drying and solidification of the coating film, thus improving the quality of semiconductor manufacturing.
Implementation Method 1
a gas nozzle configured to discharge gas to a second position on a downstream side of a rotational direction of the substrate near a rotational center of the substrate rather than to the first position on the substrate which is rotating, and provided to shape the coating film by a flow of the gas toward a peripheral end of the substrate from the second position
Data Source
AI summary
A coating film forming apparatus of the present disclosure includes: a rotation holder configured to hold and rotate a substrate; a coating liquid nozzle configured to discharge a coating liquid to a first position of a peripheral edge portion of the substrate which is rotating and form a coating film of an annular shape along a circumference of the substrate; and a gas nozzle configured to discharge gas to a second position on a downstream side of a rotational direction of the substrate near a rotational center of the substrate rather than to the first position on the substrate which is rotating, and provided to shape the coating film by a flow of the gas toward a peripheral end of the substrate from the second position.